Hondaman started this thread for comments on his devise which also allows questions about his product. I have no clue as to why you guys are getting mad ( I mean that ).
Let Hondaman answer the question I am asking, you guys have turned it into a sideshow, if HM does not want to answer/bother he can say so here.... that's fine and I'll make my own conclusions, but my Q still stands no matter what any of you post.
Well, Spanner...I'm sorry you aren't an Electrical or Electronics Engineer, or this would be easier.
The essence of what makes the Kettering Ignition system work is actually stored energy, including the energy still stored after the spark discharges. (For those of you who have my book, look into the long-winded, detailed explanation of this in section V, pages 18-23.) For every spark that is discharged, there is still approximately 23% of the power left in the circuit: this is the energy that is used to tune the electronics (quite a bit more than "a transistor switch", BTW) to control the next coil charge cycle. Careful control of charging rates causes complete charging of the coil, which then produces maximum spark. Short of embarking into electron physics, which left the readers blank last time I tried it here (in 2006), that's about the most succinct explanation I can give you.
DYNA has something that appears similar to Mark's ignition: http://www.dynaonline.com/skins/products/accessories/Dyna_Boosters/
Methinks Mark can make similar claims.
Years ago, Dyna made the "Dyna III" ignition, which is a transistorized high-current switch that runs from their Dyna S triggers. Originally, it was intended to run low-ohm primary coils like their 3-ohm "green" coils, as the original Dyna S could not handle them. Some riders simply bought the box itself and installed it, letting the points trigger the transistors: very inventive! It saved points from wear, a lot. Dyna then started marketing their box separately, and apparently still do! Mine has taken the method one step further with the stored charge/rate control coil charging circuitry I added.
Hondaman:
Just wondering... It sounds like you're using a bipolar to switch with (.3v drop). Any thoughts to use a fet with a very low Rds like .015 ohm or so? I use these on my CDI I designed for my 750's and they really are efficient devices.
I considered them, but in the past I have also experienced several problems with FET drives in these apps. Not the least is their temperature sensitivity: at subzero temps (and yes, bikers do ride then) their bias points shift so far that you have to add compensation circuitry, which adds cost and complexity. Then there's the matter of generating a negative-cutoff pulse for the gates: this has always been the Achilles Heel of those devices. If you're in a bipolar power supply it is easy to ensure the negative drive will always be there: if not, it has to be charge-pumped into existence. This is where the failures typically occur after some years pass: the capacitors commonly used to pump these voltages down below gate cutoff change value over time (like the condensors in our bikes) and the cutoff voltage starts rising toward zero, which won't turn off the FET fast enough. As it does, the FET ends up being shut off slower and later in the waveform, which causes it to heat, which changes the channel resistance, and soon the gate barrier begins to migrate away. This causes impedance changes in that gate (especially in junction FETs), which then leaks off more of the pumped gate cutoff pulse, and failure from overheating usually follows.
(Did I mention that I am a professional Electronics Forensics Specialist by trade?).
I'm going out to rebuild some swingarms and relax.
